AceShowbiz -

Neil Patrick Harris and David Burtka are added to "American Horror Story: Freak Show" which premiered early this October. The couple is confirmed to appear on the final episodes of the FX horror anthology series' fourth season.

According to TVLine, the Barney depicter of "How I Met Your Mother" is expected to portray a "chameleon salesman" in the last two episodes while his husband will have a "sexy storyline" with Jessica Lange's character Elsa Mars in the series finale.

Harris and Burtka were initially asked to guest star in the first season in 2011. They were forced to turn it down because they just finished playing an unhappy couple in "A Very Harold & Kumar Christmas" and the roles offered on the show were too similar.

"We had just played ourselves as a couple not getting along, and I thought, 'It just seems weird to do that twice, as individual actors to play a couple that hate each other twice,' " Harris said on SiriusXM. "So I said 'No,' that we shouldn't do it."

The actor who also guest starred on Ryan Murphy's "Glee" went on, "Then wouldn't you know, 'America Horror Story' is a big gigantic success and super awesome. We are big followers and fans of that show. Fingers crossed, we may get to be on it some day."

"He's game; he had very specific ideas about what he wanted to do and I have specific ideas. We're working on melding those," the show's creator later responded in a different chat. "I'd love to see him and Jessica Lange go at it in a really fun way and Neil seems intrigued by that notion. We're inching forward."